The ratio of light speed to the area of the universe is so stupidly small that I'm convinced our simulation is determining how low the speed of light can get before interstellar travel is outright impossible.
With sufficiently advanced technology, travelling between stars will be more of a transfer of your consciousness using interstellar WiFi (remember to set TCP_NODELAY!) rather than transporting slow and heavy atoms. You just get transferred from one biological substrate to another. None of the time dilation, all of the space exploration.
Sounds like a copy, not a transfer. If you didn't physically transport the atoms, the matter, you would end up with two duplicates living at different places and time, and with different ways of thinking after the copy, as the living experiences will diverge from that moment.
This unless you exterminate the original with each copy. Also should be considered each copy may lose information, degrade (signal integrity through distance, number of travels, and so on).
sure, but I don't even know how to differentiate between copying my brain and being in a coma, or just falling asleep really deeply. waking up sometimes feels like enough of a discontinuity
Idk I'd say that the clone theory also applies to our every waking moment, each fraction of a second we're no longer the same person, even in the same body.
I don't know if there is true continuity. As we age our memories become memories of memories. Just as we don't see the nose between our eyes I think our brains turn a stuttered disjointed consciousness into what seems like a continuous stream.
It's like walking into a room and forgetting why you walked in there.
How does the receiving technology get built? Surely at least someone will have to go there the first time, and they will have to take the long way. It will still be quite a problem to get to a system 10k light years away.
You just have to first hack (or maybe even just ask nicely) another suitable species (or their technological artifacts) wherever you want to go, and have them create the biological substrate and download/upload mechanism on their end. This limits travel to already inhabited corners of the universe, but that's better than nothing I suppose.
The tricky thing is that hacking is usually an iterative process, and these iterations are going to be an extreme exercise in patience.
Actually, another tricky thing: how do you know that the other end is actually cooperating? If the aliens are dicks they could give you the thumbs up while having zero intention to reconstitute your consciousness. If you wanted to round-trip some brave soul as a means of verifying everything works, they could just send one of their own minds back instead, just for the fun of wreaking havoc.
> The tricky thing is that hacking is usually an iterative process, and these iterations are going to be an extreme exercise in patience.
No kidding! On the first try you accidentally end up causing a revolution because the targets/specimens ended up learning about the scientific method, gunpowder, and other dangerous things instead of just getting a proper advanced consciousness installed. So now all you can do is try to shape said species technological progress towards building the correct technology that you can hijack for your own purposes when ready.
> You just have to first hack … another suitable species (or their technological artifacts) wherever you want to go, and have them create the biological substrate and download/upload mechanism on their end.
I presume humans are the result of such a hack a few billion years ago.
Interstellar travel require patience, at least to get beyond the initial latency.
My inner sci-fi geek tells me that by this time, we discover faster than light travel, only it isn't compatible with life as we know it.
So we ship off these receivers to circumvent that limitation. Instead of travelling ourselves, we can send off our consciousness to inhabit a human-life analog to explore.
What that does to your psyche, and your body in limbo, are probably good material for a story, if it hasn't already been written.
My inner geek tells me it's more likely humans will plug themselves into the matrix because it'll be far more receptive to technological advances than actual exploration.
At best, you'll throw a bunch of nanoprobes everywhere to get new entropy into the system.
Is YC accepting applications for interstellar body rental stations like Hertz is for cars? I'd bootstrap it, but I think this requires venture scale funding.
In elementary school I read a kids' novel, called My Trip to Alpha I, that had precisely this as a McGuffin. The main character travels to visit his aunt and uncle by "Voya-Code", in which his consciousness is transmitted to an android body on the destination planet.
Of course, everything is. Doubling the speed of light means your network packets get there twice as fast, but accelerating matter to relativistic speeds, which too is limited by the speed of light, has less marginal utility from the doubling when it comes to energy needed for acceleration/deceleration and time dilation.
You're thinking of latency vs bandwidth/throughput. You might not improve on the latency part (speed of light), but you can increase the bandwidth (amount of data transferred per unit of time) just like a highway with more lanes can carry more people without increasing the individual speed of cars. You might even decrease car speed and still get an improved throughput overall.
Maybe quantum entanglement, where the original "portals" would be set up around the universe at the speed of light, but then data could henceforth be transferred between the portals at the speed of entanglement.
I’m of the view that you can possibly duplicate consciousness but you can never send “me”. I’m stuck on the consciousness I’ve got. If you tried to upload my consciousness somewhere I’d still be sitting here like “hey look there’s another one of me”, but I’d not experience some shift in perspective myself.
No, you are your consciousness. The self exists only in the story the mind tells itself, so both versions would think they are the original you.
Besides, the serialisation process is a form of quantum measurement. Depending on how coarse-grained it is, there might be no way to take a snapshot without modifying you (maybe the measurement process turns the original brain matter into soup).
They would think they are the original you, but I think the GP was saying that the original perspective would continue on the original consciousness-continuity/body/hardware.
Cloning a hard drive can produce the same data, but without any networking, there's no reason for the original machine to know anything from the perspective of the new one
So by sleeping and breaking your consciousness stream, you die, and a new consciousness wakes up thinking it is you. With your memories and physical makeup.
Need to Ship of Theseus your neurons with digital equivalents. Every cell in your body is replaced within seven years, so can be a gradual digitalization.
Exactly what I was thinking. Note however that most neurons in your brain never get replaced naturally. An interesting extension of this idea is to replace one biological neuron with two digital copies, doing the same thing in parallel. Eventually two brain copies can be created with shared or duplicated consciousness.
I find this a scary topic, like touching a hot stove. Try as hard as I can but I can't figure out (and overall nobody has so far) how the "self" experience works.
Or is it the ratio of your lifespan to the age of the universe? The universe is only about 3x bigger instantaneously than it is when transversed at lightspeed. The ratio of the age of the universe to your expected lifespan is about 8 orders of magnitude.
That only matters if we're the most special species in the universe. I'm not ready to make that leap of faith.
On the other hand, there exists two spots in the universe that are so far separated from each other that they observers in both spots will never be able to see, affect, or pass information between each other, simply because they're too far away and the speed of light is too slow. That's silly.
"speed of light can get before interstellar travel is outright impossible"
Time is relative to your frame of reference. If you travel to Proxima Centauri at 99.99% c, it will take you 22 days from your point of reference sitting in the spaceship, which is quite acceptable. On Earth, 4.24 years have passed. So, your family and friends grow old quite fast when you do interstellar travel without them; hence, it's better to take them with you.
Oh but the speed of the signal does depend quite a lot on the transmission medium. In Cat-6 signals travel 2/3c. Can't find a quick reference for on-die or motherboard kinds of interconnects. If you had optical interconnects traveling through vacuum in a silicon chip, that's a full 50% faster (as in lower travel time for one bit over a distance) than Most copper ethernet.
Controllers kind of do that. At the end of the day, it's what makes designing a memory controller so difficult (and I'm not even talking about the Phy, those things are straight up cursed!) We see these eye popping numbers for maximum potential bandwidths, but the reality is a bit more complicated. There's a lot that goes on behind the scenes with opening and closing memory banks, refreshes, and general read and write latencies. Unoptimized prediction algorithms (as they are programmable) can result in losing _half_ of your performance.
Pipelining helps, usually. You can have 10 stages run at 3 GHz instead of 1 stage at 300 MHz. Up until you have a branch misprediction and have to dump the pipeline.
Memory channels are independent, however generally all cores use all channels. There are two common designs. Intel has 4 dies, 2 memory channels per core, so 2 channels are closer/lower latency than the other 6. AMD has multiple chiplets, but a single memory controller with 12 channels. So All cores have the same latency to all channels.
Generally Intel has lower latencies to 25% of the channels, but AMD has more throughput (bandwidth or random IOPs).
One thing that surprised me is that for maximum throughput you want at cache misses queued to the memory controller, at least twice the number of memory channels. These days missing in L1/L2/L3 is often approximately half the total memory latency. So on an Intel Xeon at least 16 misses (per socket), AMD at least 24 misses (per socket.).
So on Intel you could tune things (and the NUMA support helps) to prefer the local channels. Most OSs help, and C calls like numa_alloc_local() allows local control.
For memory intensive codes I have found the best scaling when there's 2 cores per channel. Of course most codes are pretty friendly.
I highly doubt that. With on-die ECC and the ridiculously complicated PAM3 encoding/decoding, I would bet that latency is going to increase over GDDR6.
as the press release says PAM3 sends 3 bits in 2 bit times whereas NRZ would require 3 bit times to send 3 bits. that, coupled with the increased WCK for shorter bit times, suggests latency shouldn't necessarily increase.
I assume by "the ridiculously complicated PAM3 encoding/decoding" you are referring to section 2.9.3,
"The total burst transfer payload per channel is encoded using 23 x 11b7S and 1 x 3b2S for the data, 6 x 3b2S for the CRC and 1 x 2b1S for the SEV/PSN, it adds up to the 176 PAM3 symbols that can be allocated for a 16 burst over 11 data lines."
that does seem complicated using 3 (11b7s, 3b2s, 2b1s) different modulation schemes in 1 burst.
> PAM3 sends 3 bits in 2 bit times whereas NRZ would require 3 bit times to send 3 bits
Yes, but the transactions are still 16 WCK half cycles (beats) just like in GDDR6. The designers opted for a narrower bus (per channel, and more of them) rather than shorter transactions. So that doesn't save any time. I didn't find anything on the WCK rates, but it looks like they're pretty similar to GDDR6 based on all of the examples I was able to find. So I'm not convinced of much of a time savings there either.
Now, latency numbers are measured in units of tCK, not WCK, and with GDDR6 those were pretty long relative to the time it took to actually send the transaction (2 tCK.) I'm not too familiar with the internals of the DRAM, but I assume that the process of loading the data into and out of the DRAM cells is a bit involved if it takes that much time. If that were to be sped up, then we could see improvements in latency, but I'm not holding my breath.
